Serving tray mounted loud-speakers



May 22, 1956 l. w. MASTIN 2,7 6,

SERVING TRAY MOUNTED LOUD-SPEAKERS Filed June 1, 1954 INVENTOR. /l/A/\/n/ MAST/N BY w wzm A TTOQ/VE V5 SERVING TRAY MOUNTED LOUD-SPEAKERS IvanW. Mastin, Bellingham, Wash.

Application June 1, 1954, Serial No. 433,485

3 Claims; (Cl. ISL-31) The present invention relates to mountingsforloudspeakers such as used for radio receiving sets, communicationsystems, and the like, and is directed particularly to the mounting ofsuch a loud-speaker unit on a serving tray.

An object of the present invention is to provide a combination of aloud-speaker and a serving tray which will afiord effective operation ofthe loud-speaker, although the loud-speaker is mounted unobtrusively.More specifically, it is an object to improve the volume and tonalqualities of a small loud-speaker by associating it with a serving tray,without in the least impairing the value of'the serving tray for itsnormal use.

It is also an object to mount a loud-speaker on a serving tray in aposition such that the appearance of the tray is not impaired, yet itwill be convenient to connect the loud-speaker to a radio receiving set,or to a communication system, and a further object in such an assemblyis to enable the operation of the loud-speaker to be controlled readily.

Additional objects of the loud-speaker and serving tray combination ofthe present invention will be pointed out in the following detaileddescription of such a combination shown in the drawing.

. In general, the combination may include a small loudspeakerincorporating a cone within a housing, having a flange projectingoutwardly generally coplanar with the cone. serving tray to locate thecone opening close to such serving tray'bottom. Leg bars may be securedto opposite ends of the tray, and a jack and switch electricallyconnected to each other and to the loud-speaker may be mounted in one ofthese leg bars.

The drawing is a bottom perspective view of a serving tray on which aloud-speaker is mounted, parts of the tray and loudspeaker housing beingbroken away to reveal structural details of the combination.

So-called drive-in restaurants are prevalent in many areas of the UnitedStates and since the present invention is particularly suited for use insuch establishments, theinvention will be described with reference tothe requirements of such use, although it will be understood thatsimilar combinations of loud-speakers and serving trays may be used incafeterias or restaurants of other types. In many restaurants individualloud-speakers are provided at each table to supply music for theenjoyment of the customers. The availability of such music isparticularly attractive to young people. Drive-in restaurants also havebeen most popular with young people, but it has not been possible toprovide music for individual automobile customers at a drive-inrestaurant heretofore.

Drive-in restaurants have achieved their popularity because of theability of automobile occupants to be served without getting out of theautomobile. The automobile occupants have greater privacy than in theusual restaurant and less effort is involved in eating in onesautomobile than in getting out of the automobile and going into the Thisflange may be secured to the bottom of a 2,746,559 Patented May 22, 1956its restaurant. The convenience of serving patrons in driveinrestaurants has been greatly improved by providing serving trays onwhich food can be carried and which can be attached to the automobilewithin easy reach of an occupant. A serving tray type which has provenpopular for this kind of service is shown in the drawing as arepresentative style of tray for incorporation in the present invention.

The conventional type of serving tray mentioned above includes the trayproper having the imperforate bottom 1 with sides 2 extending upwardfrom the bottom around its margin. Across opposite ends of the trayextend leg bars including an upper flat strip 3 having its opposite endsriveted to the tray and a lower strip 4 secured in faceto-facerelationship to the strip 3 over most of its length, but having its endportions first offset and then bent at an angle to its main portion toform leg elements 5 projecting away from the tray. Such leg elements maybe covered with tubular rubber strips 6. I

Across the central portion of the tray parallel to-tne leg bars 3, 4 issecured a strap 7 the central portion of which is spaced from the traybottom. The opposite ends of this strap may be riveted to opposite sideflanges of the tray, as shown, or to the tray bottom. A brace 8 has oneend adjustably connected to the strap 7, and its other end provided withan anti-skid foot 9, such as being formed of rubber material. The end ofthis brace connected to the strap 7 may have a notch in formed betweentwo lugs 11, which fit over the strap, and such lugs are connected by arod 12 extending across the face of the strap remote from the braceproper. Such connection enables the strap-engaged end of the brace to beshifted along the strap 7 into any position desired.

Such a serving tray may be attached to the side of an automobile byengaging the legs 6 over the upper edge of a window when slid downalmost to the bottom of the window opening. The upper end of the brace3' may then be moved along the strap '7 to a position corresponding tothe angle at which it is desired to set the brace, and the foot 9 isthen engaged with the side of the automobile beneath the window openingto support the side of the tray opposite the legs engaged with theautomobile window; When the tray is not in use'the end of brace 8engaging strap 7 may he slid along the strap and the brace swung upwardover the strap until lugs 13 on opposite sides of the brace near thefoot 9 pass through opposite notches in in the strap, and as the braceis slid further along the strap these lugs will hold the brace inretracted position closely underlying the strap 7.

A loud-speaker ItS may be combined readily and advantageously with anautomobile serving tray, of which that described above is anexample. Theloud-speaker includes the cone 1' 5 and preferably is substantially enclosed within the housing 17. This housing has a flange 18 which issubstantially coplanar with the Opel-ling or" the cone 16. The flange issecured to the impcrforate tray bottom 1 with the cone opening adiacen'tto such bottom. This attachment may be eflected by bolts 19 extendingthrough the respective corners of the flange 13 and the tray bottom,and, if desired, a gasket 26 of felt or rubber strip material may beinterposed between the loud-speaker housing and the tray bottom.

The combination of such a loud-speaker and serving tray in this fashionhas many advantages. It is important that the combination of aloud-speaker with a tray not impair the utility of the tray for itsintended purpose of serving the occupants of an automobile. Also, theloud-speaker should be mounted so that it cannot be damaged readily andis not unsightly. If a loud-speaker were simply placed on the tray, itcould easily be knocked off, and, to the extent of the space which itoccupied,

the bottom of the tray, the entire upper surface of the tray can be usedin customary fashion. Also, there is little danger of the loud-speakerbeing struck and injured by dishes, as it might be if mounted on theupper surface of the tray oron the tray edge. Furthermore, theimperforate upper surface of the tray can be washed thoroughly to keepit clean without danger of injuring the loud-speaker when mounted on thetray bottom as described.

While the advantages of mounting the loud-speaker on flte tray bottompointed out above are important, the most important advantage is in theenhancedutility of the loud-speaker itself. It is customary when thetrays are not in use to stack them one upon another. Also, when such atray is loaded with food it is quite heavy. Consequently, in order to beable to mount a loudspeaker on the tray bottom as described it must becompact and light. At the same time, such a loud-speaker is of littleutility if it is. not sufiiciently powerful to enable the occupants ofthe automobile on the outside of which the tray is mounted to hear musicor a message broadcast by the loud-speaker. It is important, therefore,that the operation of the small and light loudspeaker be made aseifective as possible.

Some directional qualities may be given to sounds emanating from theloud-speaker by providing a grill 21 in the side of the housing adjacentto the edge of the tray next to the automobile window. By far thegreatest effectiveness in the propagation of sound from the loudspeakeris attained, however, by securing the loud-speaker in a position withits sound wave propagating side, in the instance shown the concave sideof the cone, adjacent to and preferably engaging a principal surface ofthe imperforate tray. This disposition of the loud-speaker converts theentire tray into a sound propagating diaphragm energized by thevibrations of the loud-speaker cone 16. Both the tone and volume ofmusic produced by the loud-speaker are greatly improved by thisdiaphragm reproduction action of the tray itself.

Since thehousing 17 does not contribute appreciably to the production ofthe sound because it is small relative to the size of the tray as awhole, it may be made as a one-piece plastic part, and while the trayalso may be made of plastic, it is preferred that it be of metal such asof aluminum alloy material. It has been found that the sound-producingefliciency of the tray as a diaphragm is not appreciably impaired bydishes on the upper surface of the tray, although frequently paperplates and cups are used for drive-in restaurant service.

It is, of course, not practical to support a complete radio receivingset on a tray, so that whether the loudspeaker is to reproduce musicfrom such a radio receiving set, from a phonograph, or is to be used toconvey a message as in an intercommunicating system, it is necessary toprovide for an electrical connection to the loudspeaker at the locationof the automobile. Such connection is afforded by mounting on one of theleg bars 4 v between the strips 3 and 4 a jack 22 into which a plug 23can be inserted. This jack is preferably mounted at the end of a leg barremote from the end to be engaged with the automobile window. For thispurpose it is merely necessary to extend the end of strip 3 and to bendsuch strip end downward to form a recess as shown, in which the jack 22is received. The electric wire 24 carrying the plug 23 may be mounted inany suitable manner at the car-parking station and connected to thecircuit of a radio receiving set, a phonograph or an inter-.

communicating system.

In use, an attendant in filling the order for patrons in an automobilewould mount the tray on the sideof the automobile by use of the hookedlegs and brace in the usual manner. .The attendant would then insert theplug 23 into the jack 22. Because this plug and jack is at the side ofthe tray remote from the automobile,

it is not convenient for an occupant of the automobile I to reach it.Consequently, it is preferred that aswitch switch 25 is received. Theswitch, jack .22, and loudspeaker may then be suitably interconnected bywires 26, enabling the loud-speaker to be energized or deenergized atwill by manipulation of the switch and without the necessity of removingthe plug 23 from the 'jack 22; I claim as my invention: i p 1. Incombination, a serving tray, a loud,-speaker;including a cone, and meanssecuring said loud-speakervto the bottom of said tray for vibrating saidtray to disseminate sound, the upper surface of said tray being unbrokenand unobstructed, having unimpaired utility for use as a serving tray.2. In combination, a serving tray, a loud-speaker in-. cluding a cone,and means carrying said loud-speaker beneath said tray with the vconcaveside of said cone facing, adjacent to and closed by the lower surface ofsaid tray for vibrating said tray to disseminate sound, the uppersurface of said tray being unbroken and imobstructed, having unimpairedutility for use as a serving tray.

3. In combination, a serving tray, a loudespeaker in- 1 References Citedin the file of this patent i p UNITED STATES PATENTS,

1,882,401 Pierce Oct. 11, 1932 1,893,893 Hammond Ian. 10, 1933 1,899,929Andrews Mar. 7, 1933 2,160,112 Van Urk et al May 30,1939 2,341,275

Holland Feb. 8, 1944

